What Causes the Engine Fault Light to Illuminate After an Oil Change?
2 Answers
After an oil change, the engine fault light may illuminate due to the following reasons: 1. Faulty spark plugs, ignition coils, fuel pump, or clogged fuel lines in the engine; 2. Poor contact in sensors such as coolant temperature, crankshaft position, air flow, intake air temperature, or oxygen sensors; 3. Poor oil quality leading to engine wear and triggering the fault light; 4. Excessive carbon buildup causing deviations from the engine's designed parameters. The function of an engine is to convert the thermal energy of gasoline or diesel into mechanical energy by burning the fuel in a sealed cylinder, where the expanding gases push the pistons to perform work. Internal combustion engines typically transform chemical energy into mechanical energy.
I just helped a friend change the engine oil, and then the check engine light came on. This situation is actually quite common, possibly because the technician accidentally loosened the connection of the oil pressure sensor during the replacement process. The sensor is used to monitor oil pressure, and if the connection is poor, the system will falsely report a fault code, triggering the warning light. Another possibility is that the oil filter wasn't installed tightly enough, causing a slight leak and affecting the oil pressure reading. Sometimes, the viscosity of the new oil is incorrect, such as using oil that's too thin, and the computer thinks the oil pressure is insufficient. I suggest first checking the oil dipstick to confirm the oil level is adequate. If it's full and normal, try restarting the engine or resetting the computer. If you still can't find the cause, it's best to drive to a professional repair shop and use a diagnostic scanner to read the fault codes, which can quickly locate the problem. Don't ignore this light, as it could lead to the engine operating under low oil pressure for an extended period, accelerating wear and tear.
